John Curl's Blowtorch preamplifier part II

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The theory behind that way of teaching, as I understand it, is that technology changes rapidly, so your limited time in school should be used to learn things with a long half-life, which is to say a lot mathematical theory. The other part of it is that you are much more likely to get through learning math if you keep up your momentum in school and keep learning and practicing (learning by rote) with it faster than you can forget it. Unlike learning the technology of the day, if you don't learn mathematical theory in school, its unlikely you will do it on your own later. But, yes, schools do graduate people who can do math problems from a book and are otherwise lost in the real world. And, yes as you describe, I can think of the physicists I know who made it through Jackson (electrodynamics) and can't remember much about it now.
I agree heartily that math is the toughest for self-study. It is also essential unless you have elected to play in the numeric domain exclusively.

A good tutor can be helpful, also very difficult to find.

I have worked with good electronics engineers who never got the maths down, and you could see how crippling it was. When I started at one company I was assessed for my skills at that moment, and was told of another employee who was described by my immediate boss as "scary". It turned out that the guy, who had a Master's from MIT, had a modicum of math that the boss and his boss had determined was permanently out-of-reach for them, such as being able to do complex algebra and play with simple linear-system transfer functions---although most of the time he just did simulations like so many, and got decent answers.

What disappointed me though: my own skill set in 1990 was hardly static, but I could see that the initial assessment was going to stick indefinitely. At the age of 42 my growth was considered ausgespielt.

This is one reason why the best policy is often to stay in school almost as long as possible, even though ideally one would benefit from "real-world" experience interspersed with the studies. But what frequently happens is one gets some money flowing, upgrades the standard of living, gets married and has kids. The continuation of the theoretical education becomes a receding image that becomes ever less likely.
 
Now I really must work out what I want to do with my life when I grow up :)


I flat out refuse to do that.

Grow up, that is...

The theory behind that way of teaching, as I understand it, is that technology changes rapidly, so your limited time in school should be used to learn things with a long half-life, which is to say a lot mathematical theory. The other part of it is that you are much more likely to get through learning math if you keep up your momentum in school and keep learning and practicing (learning by rote) with it faster than you can forget it. Unlike learning the technology of the day, if you don't learn mathematical theory in school, its unlikely you will do it on your own later. But, yes, schools do graduate people who can do math problems from a book and are otherwise lost in the real world. And, yes as you describe, I can think of the physicists I know who made it through Jackson (electrodynamics) and can't remember much about it now.
My schooling was more theory and thinking. Not so much rote, but figuring out.

Now, it's more of an immersion thing. It also helps when the work is in front of the leading edge of technology, at least in some aspects...totally heaven I tell ya...

John
 
That may be your difficulty.



No. If you actually believe this, then that may be the other part of your difficulty.

Be specific if you do not wish to state any generalities.

ARE THERE ANY situations where one of these super regs will be audible to YOU vs. a standard "good" 3 pin?

hows that.


And which properly conducted DBTs have revealed anything other than fairly gross differences? Happy to know about them.


Dance, dance, dance...

_-_-
 
Today reading the latest IEEE Spectrum 7.16 I find that most of what I learned in the last 60 years is pretty much passe, but of course it can be still useful.
This issue talked about practical nanotube based computers, DNA based storage, and Quantum research in general. WOW! Maybe Bybee is on to something. '-)
 
Today reading the latest IEEE Spectrum 7.16 I find that most of what I learned in the last 60 years is pretty much passe, but of course it can be still useful.
This issue talked about practical nanotube based computers, DNA based storage, and Quantum research in general. WOW! Maybe Bybee is on to something. '-)
Then again, it could be just a case of stealing buzz words.

John
 
RNMarsh said:
The reason the L is greater in the center is because that is where the flux density is greatest.
That cannot be true. The total flux around a closed curve is given by the total current going through the area enclosed by the curve. If the current is mostly at the surface of the wire then inside that surface there must be very little flux. Basic first-year EM.

davada said:
Ask Sync. He is in the midst of it right now.

Prof "All pots are the same. If you set them at mid point you get exactly half the resistance.

Sync " But what about log pots."

Prof " What the hell is that. There is only one kind."
It is true that some EE profs lack practical experience in electronics. That does not mean that their theoretical teaching is necessarily wrong or irrelevant - although sometimes it is, and needs to be corrected by the correct theory as found in the better, more advanced textbooks.
 
john curl said:
Today reading the latest IEEE Spectrum 7.16 I find that most of what I learned in the last 60 years is pretty much passe, but of course it can be still useful.
This issue talked about practical nanotube based computers, DNA based storage, and Quantum research in general. WOW! Maybe Bybee is on to something.
I just read that too. Nothing in there to undermine my education, and nothing to support the Bybees of this world. Maybe you saw a different version from me?
 
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They have greatly improved the page. Back a few years, it was abysmal.

They now include bessels and when they are appropriate..nice.

I'm glad they included the toroidal eddies in the wire I spoke of. I posted that depiction about two years before H. Johnson included it in his book, now I see it everywhere. Good, that's as it should be.

I love the explanation of coax vs frequency..very good.

They should also include a depiction of a coax that has been deformed with core off center, to show how the current will redistribute as frequency increases to force the shield current to go back to common centroid.

They should also include the depiction I linked to a few posts back with the equation below and above the wire surface.

John

Good -- thanks for the comments. I thought it seemed fairly good, but after some of the dialogue here you start to wonder... And wiki can be a tad variable... :)
 
diyAudio Member RIP
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The generally dismal level of engineering education today leads to what I call app note designing, essentially stringing together application notes in a cut-and-paste fashion. Even with this, which is done to speed up the design process and assure success, and please managers, things still go wrong. There is not a lot of innovation, which suits the suits, at least for a while.

In the proverbial good old days, people who entered electronic engineering school were already experimenter/hobbyists. Even other disciplines like physics and astronomy had undergrad and grad students who were handy with gadgets. By the time I started to work for UCLA on the nonacademic staff, there were only a couple of people in the astronomy dept. who were comfortable with such things, and I was hired in because one of them was doing too much gadgetry and not getting his dissertation done.
 
Page 29 of the IEEE Spectrum 7.16 mentions a paper that Jack Bybee recommended to me about 15 years ago. Here it is. I would never have been exposed to it without his input. It gave me a 15 year head start so to speak on electrical conduction compared to many here.
 

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Page 29 of the IEEE Spectrum 7.16 mentions a paper that Jack Bybee recommended to me about 15 years ago. Here it is. I would never have been exposed to it without his input. It gave me a 15 year head start so to speak on electrical conduction compared to many here.
What is even more interesting, is I can duplicate it with insulated magnet wire.

By using a straight length of magnet wire and immersing it in mercury, the conduction remains the same after initial contact, no matter how deep I push the wire into the metal. Clearly, a length of magnet wire will exhibit quantization. So I can make devices with copper powder and sell a lot of them at high cost, right??

The researchers have lots of work left to do. Ballistic electron movement is consistent with vacuum tubes as well as superconductivity. The problem with ballistic transport is not in the middle, it's at the end..

If you want, just ask the researchers of the paper about bybees.. However, a warning. Do NOT ask them at lunch, especially if one of them is taking a drink. Fluids coming out the nose is not a pretty sight.

John
 
The generally dismal level of engineering education today leads to what I call app note designing, essentially stringing together application notes in a cut-and-paste fashion. Even with this, which is done to speed up the design process and assure success, and please managers, things still go wrong. There is not a lot of innovation, which suits the suits, at least for a while.

In the proverbial good old days, people who entered electronic engineering school were already experimenter/hobbyists. Even other disciplines like physics and astronomy had undergrad and grad students who were handy with gadgets. By the time I started to work for UCLA on the nonacademic staff, there were only a couple of people in the astronomy dept. who were comfortable with such things, and I was hired in because one of them was doing too much gadgetry and not getting his dissertation done.


Corporate wants product development. Not engineering.
 
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